This invention relates to a method and an apparatus for severing a sliver during the coiler can replacement in a drawing frame. According to a known method, as sliver deposition takes place, during the coiler can replacement the distance between the sliver coiler, for example, the sliver outlet opening of a rotary coiler head and the uppermost sliver layer in the coiler can is increased to such an extent that the sliver ruptures.
According to a known method described, for example, in German Offenlegungsschrift (application published without examination) 33 24 461 the coiler can filled with sliver has to be rapidly moved away to obtain rupture of the sliver. The rupturing force is derived from the difference between the speed of the coiler can moving out from under the coiler (such as a rotary coiler head) and the velocity of the sliver discharged by the sliver coiler. When the coiler can is full, the sliver delivery speed is switched from "fast" to "slow". It is a disadvantage of this conventional method that the sliver cannot run with the normal (high) operational speed during the coiler can replacement process. It is also a drawback that the heavy, filled coiler can, because of its inertia, cannot be moved away sufficiently rapidly. As a result, the sliver may not rupture with reliability particularly in case of different sliver thicknesses and/or different types of fiber material.